Key Points
- Hazard control burning is a widely used but contested method of reducing the risk of catastrophic bushfires.
- Critics say it's at best ineffective, and at worst increases the long-term danger by creating extra flammable fuel.
- Indigenous fire practitioners say their methods offer long-term solutions, but their knowledge is being ignored.
Some 5.3 million Sydneysiders awoke on Thursday morning to find their city swaddled in some of the world's most heavily polluted air.
Authorities insisted there was a good reason: with temperatures forecast to hit 30C over the weekend, the NSW Rural Fire Service (RFS) was rushing to complete hazard reduction burn-offs in Sydney's north, west, and south.
A fearsome bushfire season is setting in fast, and this could be one of the last opportunities to reduce the fuel load.
What are hazard reduction burns, and are they effective?
Hazard reduction burns, often referred to as "prescribed burns", are a method of mitigating the danger of large bushfires by intentionally starting smaller, controlled fires and reducing the amount of flammable vegetation.
Firefighting agencies across the country have relied on this approach for decades.
In the past few weeks alone, RFS crews have conducted burns across thousands of hectares of land, making up for lost time after only managing to complete about 24 per cent of planned hazard reduction burns since June.
It's also a controversial method, with the science surrounding its safety and efficacy hotly contested.
While some studies assert that hazard reduction burning leads to fewer fires and a greater ability to suppress them, others argue it has little to no effect in slowing severe bushfires.
Some researchers claim the practice may even increase the danger.
Cultural burns as hazard management
Meanwhile, there are growing calls for Australian governments and authorities to adopt the principles and practices of Indigenous fire management, or "cultural burning", which advocates claim is a more effective and less harmful method of bushfire risk management.
"Cultural burning is about the different ecosystems that we [Traditional Owners] manage through fire to prevent bushfires," said Robbie Williams, a descendant of the Githabul and Ngarakbul peoples.
Williams is also founder of the Indigenous-owned business Fire Lore, which provides and educates people about cultural burn services and combat the effects of fire, drought, soil degradation, and invasive species.
When it comes to hazard reduction and cultural burning, "you can't do it any safer way", Williams says.
Upside-down country
For more than 60,000 years, First Nations Australians have used cultural burning to manage the land, maintain ecosystems, and mitigate the risks posed by bushfires. This is often done using a method known as "mosaic" burning, where small areas are burned regularly to create a patchwork of natural habitats and regrowth.
Williams, who has been working as a fire practitioner for 10 years, explained that the most important aspect of cultural burning is to create small, relatively cool fires that don’t scorch the earth or burn the canopies of the trees, which form the habitats for animals, flowers, and seeds.
"When they're burning all the canopies of the trees, what they and a lot of people don't realise is that they're creating more fuel loads," he said.
"You know there's fires around when you see black wattles everywhere, which usually comes up after hazard reduction burns … and when all that dies, there's fuel loads on top of fuel loads just back there again."
Philip Zylstra, adjunct associate professor at Curtin University, explained that not only do treetop canopies serve to slow fires by disrupting the wind beneath them, they can also shed dead leaf litter and activate seed banks when they burn, which in turn leads to the growth of more flammable vegetation below.
"You are removing what's called an overstory shelter, the taller plants that slow fire, and replacing it with plants that act as fuels," he said.
"So you get this kind of hump response with fire risk, where straight after fire you've cleared things and the risk is fairly low, and then you get this dense regrowth and the risk increases very quickly."
This is what Williams calls "upside-down country": when the vegetation nearer to the ground is thick and bushy while the overstories are stripped bare. Both he and Zylstra agree that, in this way, prescribed burns can actually make things worse.
As Williams put it: "Cultural burning prevents bushfires; hazard reduction creates them".
Zylstra suggested that while neither hazard burns nor cultural burns are panaceas to Australia's bushfire threat, there are "absolutely" things that governments and authorities could learn from Indigenous fire management practice.
"I feel it's unfair to say, if we adopt Aboriginal fire management, we'll fix the fire problem … But there are huge principles we can learn from it," he said.
"I think we can redevelop a kind of cooperative approach to management where we work with the natural processes in the landscape and in the way that First Nations did and still do in some places, allowing old forests to age."
Slow burn
Much of the criticism levelled at hazard burning has to do with the idea that it’s a short-term fix with long-term consequences.
As Zylstra pointed out, "Most of the studies that historically have said that it's effective do that by looking at the very short-term perspective."
Williams further noted that his and Fire Lore's attempts to persuade bushfire management authorities to embrace the long-term, slow-burn benefits of cultural fire practices have often been foiled by a sense of bureaucratic impatience.
"How we do things, it's too slow for them," he said. "They want like a thousand acres burnt in one day, and the only way you can burn that in one day is get that fire as hot as you can and just burn everything to the ground. That's when I know there's nothing coming out, and that's going to create more fuel loads."
Firefighting boss wary of misappropriating Indigenous practices
Peter McKechnie, deputy commissioner of the RFS, told SBS News there are a number of local brigades across the state that are working with Indigenous communities to assist and facilitate more opportunities for cultural burning – while noting that it is a distinct practice that "has some very different reasons to occur than as simple as just reducing bushfire hazard."
"I think that really the key message is cultural burning is something that we need to make sure we don't misappropriate,” he said. “Can we learn from it? Can we assist Aboriginal communities to be able to do more of it? Yes.”
McKechnie also accepts that even the most efficient hazard reduction burns are not a panacea to bushfire risk, and that their benefits are greater in the immediate aftermath than they are several years down the track.
But he doesn't subscribe to the idea that they cause more issues than they solve.
"[Hazard burns] are very effective in providing strategic opportunities for firefighters and reducing the intensity of fire as it burns through an area," he said.
"We're simply looking to reduce the fuel loads, particularly across the forest floor or the grassland itself - but a burn that's six years old won't be as effective as a burn that is one year old. And that's just simply because the fuels are returning."
Fire season fears
McKechnie pointed out that the past few months in particular have seen a lot of fuel returning across large parts of Australia, as wet conditions have stimulated regrowth on the one hand while also preventing authorities from carrying out operations to reduce it.
It's a cause of concern for the RFS, he admitted, and the service is now trying to do as much as it can – including the recent uptick in hazard reduction burns around Sydney - to mitigate the risk before the bushfire season properly sets in.
But others are worried not enough has been done.
"It keeps me awake," said Zylstra. "I think the regrowth after three years now years will be extremely dense and vulnerable in many areas, so there's that risk of fires burning at much, much higher severity than we've seen in a lot of places."
A lot of areas that burned in the 2019-2020 Black Summer bushfires had already seen an intense regrowth of highly flammable species, says Leeton Lee, a Thungutti, Bundjalung, and Mualgal person who is both a cultural fire practitioner at Indigenous not-for-profit Firesticks and a volunteer firefighter with Queensland’s Rural Fire Service.
"At the moment, I'm quite worried for a lot of the country that I've seen," said Leeton. "I think we've really missed a lot of opportunities in the last couple of years to really get in and start restoring some of our landscapes."
"I don't think that from 2019-2020, and even other fires, that that message has really been listened to: the message that we need to get the right fire back on country."
